Hydraulic indexing mechanism



July 21, 1953 E. J. HlRvoNEN HYDRAULIC NDEXING MECHANISM 8 Sheets-Sheet l Filed Jan. 5, 1949 A JNVENTOR. EP/c J.' HffvoH EH E. J. HIRVONEN HYDRAULIC INDEXING MECHANIS`M July 2l, 1953 B Sheets-Sheet 2 Filed Jan. 5, 1949 :New

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HYDRAULIC NDEXING MECHANISM Filed Jan. 5, 1949 8 Sheets-Sheet '7 July 21, 1953 E. J. HlRvoNEN HYDRAULIC INDEXING MECHANISM 8 Sheets--SheefI 8 Filed Jan. 5, 1949 INVENTOR. 1 [mc: I H/"RVOHEH Patented July 2l, 1953 Artur ortica HYDRAULC INDEXING IWECHANISM Eric J. Hirvonen, Shrewsbury, Mass., assignor to Leland-Gifford Company, Worcester, Mass., a corporation of Massachusetts Application January 5, 1949, Serial No. 69,357

(C1. Sli-56) 16 Claims. l

This invention relates to hydraulic control systems for indexing tables such as work tables for machine tools particularly drills, milling and boring machines, etc. The principal object of the .invention resides in the improvement of operation of production tools as to the work tables, carriages, etc., thereof, and increasing the speed, accuracy, and production of machined parts, especially those requiring more than one`operation, e. g., drilling, counterboring, tapping, etc., and those requiring a, plurality of like operations, e. g., a series of even or irregular spaced drilled holes, the improved operation residing in increased speed of indexing between work pieces or work stations and in the accuracy and positive ness of locking of the table between indexing steps.

Another object of the invention resides in the provision of hydraulic means to release the index table locking means to move the index table at high speed for a predetermined interval, to slow the indexing movement thereof, and to relock the table, the slow down taking place just prior to the relooking and obviating shock and wear and allowing the use of very high indexing speeds not heretofore possible.

A further object of the invention resides in the provision of a rotary work table, a travelling tool therefor, a hydraulic motor `for the table, a cam `driven by the motor, a series of slots in the cam,

said slots being either regularly or irregularly spaced depending on the work to be done as will appear more fully hereinafter, a cam follower pin receivable in the slots one afterthe other, hy-. draulic means controlled by the position of the tool to retract the pin, hydraulic means moving the pin reversely to bear on the vcampetween slots, a low point on the cam just prior to the sequential slot, said pin of course moving stiil farther reversely according to the low point, and hydraulic means to slow the motor controlled by the last movement of the pin, just prior to the latter dropping 1'nto the sequential slot.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had tothe accompanying drawings, in which Fig. l is a plan view of an index table embodying the present invention, parts being in section; Fig. 2 is avertical section on imei-2 of Fig. l; Fig. 3 is a view in elevation looking in the direction'o the arrow 3 in Fig. 1, parts beingin sec- Fig. 4 is a diagrammatic View of the hydraulic at rest but ready to operate;

Fig. 5 isa view similar to Fig. 4 showing the parts in operation;

Fig. 6 is a diagram similar to Fig. 4 but showing the parts in another position; j

Fig. 7 is a diagrammatic view of thehandoperated valves in off position; k i

Fig. 8 is a view of the same valves in set-up position;

Fig. 9 is a diagrammatic view showingthe hydraulic system in slow rotational position relative to the work table;

Fig. 10 is a View similar to Fig. 4. with parts omitted but showing the relation of the hydraulic system to a machine tool;

Fig. 11 is another view like Fig. 4 but showing a different cam;

Fig. 12 is an enlargedV section through the adjustable regulating valve; f

Fig. 13 is a section online |3-l3 of Fig. i2;

Fig.v 14 illustrates a drilling machine to which the present invention is applied; and

Fig. 15 is a top plan view oa machine to which the indexing table of the present invention is applied. V

By way of illustration,a drilling machine D is provided with a knee K on which is located the present indexing device I, the machine having a spindle S rotated by motor M and traversed by a piston in a cylinder A. The drill spindle, when up, in non-drilling position, opens a valve yV to provide animpulse to line C from the pump P.

A source of fluid pressure which may be the vpump P, is indicated as entering` the machine as, for instance, at i0 and this fluid under pressure enters a valve housing l2 having a valve stem, lli normally held in the up position shown in Fig, 4 by means of 9. spring le. This stem is, when in the Fig. 4 position, blocks a passage iii, the latter leading to a second valve lhousing generally iny dicated at 20. The valve I@ may be urged down wardly by uid pressure in a line 22 entering the top of housing i2.

` 'The valve housing 20 is provided wlth a valve `stem 2li normally heid in its uppermost position -to operate the same. In this Way, when pressure is applied to line 32, the spindle S descends to operate on a workpiece, as will be understood byl those skilled in the art. The passage 3i] is closed by a valve part 3&1. Valve housings I2 and 20 have drains 36 and 3B leading to drain 40.

The line 23 leads rto a third valve housing generally indicated at 42 and this valve housing Vis provided with a valve stem having elements 44, 46 and 48, the element 45 closing a passage 5U which leads to a hydraulic motor 52 from passage 28, when the valve 42 is in the Fig. 4 position. An element of motor 52 is directly connected to and serves to rotate the work table 54. The hydraulic motor is provided with an exhaust line S, a branch 53 of which leads back to the valve housing 42 at the bottom thereof, and another but smaller branch 80 leads to the top of element i8 in Fig. 4.

With the valve stem in housing 42 in the position shown in Fig. 4, the line 2B communicates with a smaller line 62 which passes through the element 6d of a rotary valve having a handle 5B, this valve having passages S8 and 'I ll. 'Ihevalve' element Eli is connected directly to valve element I2 having passages 'I4 and 'I6 so that the Valve elements 84 and 'I2 are rotated together by the handle 56. The valve elements 64 and 'I2 are actually the same part but for purposes of explanation they are shown separate.

The passage 'i0 connects an incoming line `I8 connected to line C, with a passage Si) which leads back to the top of valve housing I2 at one side of the valve element 82 therein. The impulse of line C is therefore transmitted to the element 82.

The passage 68 is used to connect line v82 with a line 84 in running position of the handle S6, but if the handle is turned to the set-up position, line 8d is connected With line 78, see Fig. 8, so that the iluid impulse above described will proceed directly to the line 84 rather than to the line 88 to unlock the index table as Will be more apparent hereinafter, to allow for setting up.

The line 52 has a branch 86 containing a plug valve 88 normally held in the position shown in Fig. 4 by the spring-pressed detent 90 but which when moved down by pressure in line 62 connects line 88 with a line 92, leading to the bottom of valve housing 28 as at 94, see Figs. 5.and 6.

The line 3|) also has a branch as at 96 with a plug valve 98 therein held in its upward position by means of a spring-pressed detent |08 but which when pressed down will connect line 96 with a line |82 going to the top orvalve housing 42 above the element L14.

The worktable 54 is provided with a cam having a plurality of radial` slots |04 and a peripheral cam surface having twor main portions, one at |66 and one at |88, these surfaces being at unequal radial distances from the axle |08.

The slots |54 are for the reception. of tip H0 of an index pin H2, the same being springpressed to the right by a compression spring H3 located in a base H4. Pressure in line 84 will move the index pin H2 to the left and pressure in line H6 leading from the bottom of Valve housing 42 will push the index pin II'2 to the right in addition to the action of the spring H3.

The reference numeral |58 indicates an adjustable ow regulating valve located in the drain |20 and connected with the drain 48. The line |22 leads to the drain also.

Assuming that the drill or other machine tool is atk its topmost or inoperative position, the above mentioned impulse is applied to the pipe line 78, which impulse proceeds through the pipe 8E] to 22 and acts upon the valve element 82 to push the valve I6 down connecting the pressure line It withgthe pip-e I8. The oil then continues through valve 2.0 and pipe 28 to line 62; and the plug valve 88 is pushed down allowing oil to go to the bottom of the valve housing 25 and push the valve element 2d up, keeping it there for the cycle. The oil proceeding through the line 62 goes through the valve 64, now in run position, to the pipe line 84 and Pushes the index pin H2 tothe left out of the slot |84 in which it has been located. When the index pin is forced back by the pressure of the oil in the pipe line 84, the oil then goes from the line 8d to the line |24, see A position, Fig. 5, back through the valve element 'I2 through passage it through a constriction |28 in a pipe |28 to the inlet port at |38 of the hydraulic motor, initiating rotation thereof.

The fluid passing through the hydraulic motor builds up pressure at exhaust port |32 thereof in the line 58 so that the valve stem in housing 2 is pushed up, clearing the line 5U by reason of element 46, see Fig. 5, so the hydraulic motor then receives the full pressure from line 28, speeding up the rotation of the work table. At the same time, however, the line H5 is opened and this causes oil pressure to bear on the back of the index pin H2 which is, therefore, pushed to the right to ride on the cam surface |86 of the index table, the cam and table rotating clockwise. As long as the index pin rides on surface It, the rotation of the work table is at top speed, line I I6 being open to drain iii through the pin I2 at |28.

Line I i8 is substantially fully open to the drain at 4G when the pin i I2 rides on cam surface |06, see Fig. 5, wherein the distance A-B is the distance ci overrun to the left of the pin |2. When the recessed cam surface |88 moves to the pin,

the latter is moved to the right a sufficient distance to close oi the drain 4Q from line H, see |25 in Fig. 9, so that the pressure in line 5S rises and as thus far described, the iiuid can only escape to the drain through the regulating valve H8. rhis valve is adjustable by a screw lili) which acts to extend or retract a stem |42 having a V-shaped tapered port |44 by which means the pressure may be regulated depending on the size or orice presented thereby to the chamber |48 receiving the fluid from line |28.

The high pressure in line 56 causes the motor to slow down, slowing the rotation of the table 54, and the excess fluid opens ball valve |38 against the action of its spring Hi8 and flows into pipe Eil through port |50 and back through the motor. The spring |43 may be adjusted by a screw |52.

As soon as the index pin at I I8 drops in the next slot the pressure under the valve element 24 is cut out 'because the index pin disconnects the line 84 from |24. This valve is then positioned down because of the top pressure thereon in the pipe |36. This allows an impulseof oil to pipe line 32 which causes the drill spindle piston in cylinder A or other machine tool element to start and the plug valve 98 is also pushed down providing for oil in line |92 to push the valve 44 down. As soon as the drill spindle starts down, however, the pressure which is controlled by the drill unit cuts out and no oil passes through the valve element 54. Therefore, the valve element I4 goes up due to the spring I4 and the device is ready for the next cycle, the plug valves 88 Iand 98 having received impulses suicient to move them back to original positions.

The table indexes, stops for the drill or other tool and indexes again, as long as the pump P supplies line C, so that it is merely necessary to put an operator operated shut-off valve in line C to stop and start the entire machine. y

This valve isl usually the regular foot-operated on an-d off valve.

Referring to Fig. 15, two different kinds of work are illustrated. At-i50 is shown a machined part'having two series of holes |52, produced by passes of the drill according to the cam |54 in Fig. 1l. In this case, the steps are so many las to cause it to be convenient to narrow the tip |56 of the pin l2, but the cam surfaces are the same vas before, i. e. with high spots |58 and low spots |60, Thespacing of the slots |2'may of course be varied to suit conditions and each of the holes n |52 'could be at any odd or even spacing desired.

At |64 there is shown a more usual type of work, i. e.y a four station multi-tool set up where drilling is done at |66, counter-boring'at |68, and tap-ping yat |70, the station |12 being for loading and unloading. Of course this isonly illustrative as a great many other operations may be done by a simil-ar set up. y

In any case, the indexing device is set angularly on the table to keep the housing and lhandle: 66 out of the way of the operator and allow him to keep close to the work.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:

1. A hydraulic system for indexing a table comprising a hydraulic motor to drive the table, a cam moved by the motor, means forming a series of slots in the `a cam follower pin -receivable in the slots seriation as the cam moves past the pin, a valve, hydraulic means to move the valve, a source of hydraulic power, said valve connecting the source to the pin moving the pin out of the slots to unlock the table, hydraulic means in sequencemoving the pin reversely to bear on the cam, a line to apply fluid to the motor, said pin opening the line asit moves away from the cam, means to maintain the motor in operation, and a lowspct on the -cam just prior to the sequential 'slot allowingV the pin to move farther reversely, a drain for` the motor, the pin substantially closing the drain in the lastnamed movement thereof whereby pressure is built up at the motor outlet side and the motor is slowed just prior to the pin dropping into the sequential slot.

2. A hydraulic system for indexing a table comprising a hydraulic motor to drive the table, a cam on the table and movable therewith, means forming a series of slots in the cam, ar cam follower pin receivable in the slots seriation as the ycam moves past the pin, a, valve, hydraulic means tomove the valve, a source of hydraulic power, said valve connecting the source to the pin moving the pin out yof the slots to unlock the table, hydraulic means in sequence moving the pin reversely to bear on the cam, l-a line to apply fluid to the motor, said pin opening the line as it moves away from the cam, means to maintain the motor in operation, and a low spot on the cam just prior to the sequential slot allowing the pin to move farther reversely, la drain for the motor, the pin substantially closing the drain in the last named movement thereof whereby pressure is built up at the motor outlet side and the motor is slowed just prior to the pin dropping into the sequential slot, and an adjustable now valve and an adjustable relief valve in the outlet side of the motor.

A hydraulic system to operate an indexing table mechanism comprising a rotary table, a hydraulic motor to rotate the same, a movable said control meansis dependent on the positionl of the plunger and the speed of rotation of the table depends on the position of the plunger.

4. A hydraulic system to operate an indexing table mechanism comprising a rotary table, a hydraulic motor to rotate the same, a movable plunger to lock and unlock the table at index stations, hydraulic means to move the plunger between locking and unlocking positions, the plunger having a plurality of positions when in unlocking condition, and control means for the hydraulic motor to vary the speed thereof, means operating the motor speed control means at predetermined positions only of the plunger so that said control means is dependent on the position of the plunger the speed of rotation of the table depends on the position of the plunger, and a cam controlling the position of the plunger when in unlockingcondition.

5. A hydraulic system to operate an indexing table mechanism`comprising a rotary table, a hydraulic motor to rotate the same, movable means to lock and unlock the table at indexstations, hydraulic means to move the locking means between locking and unlocking positions, the latter having a plurality of positions when in unlocking condition, and control means for the hydraulic motor to vary vthe speed thereof, said control vmeans being dependent on the position of the locking and unlocking means so that the speed of rotation of the table depends on the position of the last named means, a cam controlling the position ofthe locking and unlocking means when in unlocking condition, and interengaging means between the cam and the locking and unlocking means to lockthe table at intervals.

'6. Hydraulic index table mechanism comprising, a hydraulic motor for the table, a hydraulic circuit therefor, a cam, a cam follower, interengaging means between the cam and follower to lock the table at intervals, hydraulic means to move the follower to disengaged position relative to said interengaging means, hydraulic means to move the follower reversely to engage the cam, means to initiate actuation of the motor I '7. Hydraulic system to index a table com- Y prising, ahydraulic motor for the table, a hydraulic circuit therefor, a cam, a cam follower, interengaging means between the cam and follower to lock the table at intervals, hydraulic means to move the follower to disengaged position relative to said interengaging means, hy-

draulic means to move the follower reversely to engage the cam, means to initiate actuation of the motor upon movement of the follower to its extreme disengaged position, and means to slow the motor upon` further reverse movement of the follower as determined by the cam, said follower being located in the hydraulic circuit as a valve.

8. Hydraulic system for operating an indexing table comprising, a hydraulic motor for the table, a cam on the table, a cam follower in the form of amaca-r 7., apin, said follower ,acting as a valve device .in the hydraulic system, said follower engaging and locking the cam and therefore the table under conditions of rest, other valve means in the hydraulic system to direct uid tothe follower at opposite ends thereof to urge the follower away from and toward the cam, a hydraulic connection to the motor from the cam follower near one end thereof so that the motor is started upon movement of the follower away from the cam, hydraulic means to drive the motor at a plurality of speeds, said last named means being controlled by the follower valve device, the latter in turn being controlled by the cam.

9. Hydraulic system for operating an indexing table comprising, a hydraulic motor for the table, a cam on the table, a cam follower in the form of a pin, said follower acting as a valve device in the hydraulic system, said follower engaging and locking the cam and therefore the table;

under conditions of rest, other valve means in the hydraulic system to direct fluid to the follower at `opposite ends thereof to urge the follower away from and toward the cam, a hydraulic connection to the motor from the cam follower near one end thereof so that the motor is started upon movement of the follower away from the cam, hydraulic means to drive the motor at a plurality of speeds, said last named means being controlled by the follower valve device, the latter in turn being controlled by the cam, said follower closing the motor drain and raising the pressure at the outlet side of the motor to slow the latter down, and a relief valve for the outlet side of the motor.

10. Hydraulic system for indexing a table comprising, a hydraulic motor for the table, a hydraulic circuit therefor, a cam, a cam follower, interengaging means between the cam and follower to lock the table at intervals, hydraulic means lto move the follower to disengaged position relative to said interengaging means, hydraulic means to move the follower reversely to engage the cam, means to initiate actuation of the motor upon movement of the follower to its extreme disengaged position, and means to slow the motor upon further reverse movement of the follower as determined by the cam, said follower being located in the hydraulic circuit as a valve,

outlet, said valve being operated upon extreme reverse movement of the follower to interengaged.

position Vof `the follower and cam.

1l. Hydraulic'system for operating an indexing table comprising, a `hydraulic motor for the table, a cam on the table, a cam follower in the form of a pin, said follower acting asa valve device in the hydraulic system, said follower engaging and locking the cam and therefore the table under conditions of rest, other valve means in the hydraulic system to direct uid to the follower at opposite ends thereof to urge the follower away from and toward the cam, a hydraulic connection to the motor from the cam follower near one end thereof so that the Vmotor is started upon movement of the followeriaway from the cam, hydraulic means to drive the motor at a plurality of speeds, said last .named means being controlled by the follower valve device, the latter in turn being controlled by the cam, a further valve to direct the hydraulic pressure to the motor or to an outlet, said valve being actuated by release of pressure at one side thereof, cut o by the follower in cam locking position thereof, said outlet directing pressure to an element having a cooperating action with the table.

12. Hydraulic system comprising a motor, a cam thereon, and a movable cam follower in the form of a valve, a main valve adapted to open or close the system, a line to the main valve to operate the same to open condition, a valve in said line, a first diversion valve to selectively direct the pressure from the main valve to the system or to a device to be operated, said first diversion valve normally remaining in position to feed the system, a second diversion valve receiving fluid from the first diversion valve and selectively directing the fluid to the motor in large volume or to one end of the follower in smaller volume, in the latter position moving the follower away from the cam, a line from the follower to the motor opened by the movement of the follower away from the cam to start the motor.

13. The hydraulic system of claim 12, wherein said second diversion valve also directs uids alternatively to the opposite end of the follower to reverse the same, and a line from the motor outlet to the second diversion valve to reverse the latter upon initiation of rotation of the motor to cut off fluid to the said one end of the follower and todirect fluid directly to the motor for high speed rotation.

14. The hydraulic system of claim 12, including a line from the output side of the motor to the second diversion valve to reverse the latter to out off fluid to the said one end of the follower and to direct fluid in large volume directly to the motor, a line from the second diversion valve to the opposite end of the follower to cause the latter to press against the cam, and a low spot on the cam which causes additional travel of the follower substantially closing the output side of the motor and slowing the same down by the consequent pressure rise.

15. The hydraulic system of claim 12 including a hydraulic line to the opposite end of the follower to cause the latter to bear against the cam, the latter having slots therein at intervals to receive the follower and lock the motor and cam.

16. The hydraulic system of claim 12 including an adjustable relief valve in the motor outlet side leading to the inlet side of the motor.

ERIC J. HIRVONEN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,366,398 Harrington Jan. 2, 1945 2,380,873 Schafer et al July 31, 1945 2,443,278 Stratton June 15, 1948 2,453,600 Soden Nov. 9, 1948 2,454,591 Brady et al Nov. 23, 1948 

